Pillow block



June 7, 196 c. HILTON 3,254,926

PILLOW BLOCK Filed April 16, 1962 INVEN CARL HILT United States Patent 3,254,926 PILLOW BLOCK 0 Carl Hilton, Chicago, 111., assiguor, by mesne assignments, to Masten Corporation, Chicago, 111., a corporation of Illinois Filed Apr. 16, 1962, Ser. No. 187,752 2 Claims. (Cl. 308-72) This invention relates to the production of a novel pillow block.

More particularly the present invention relates to a new and improved self-aligning pillow block.

It is a particular object of the present invention to provide a novel one-piece pillow block wherein the bearing is non-rotatably but pivotally retained therein whereby self-aligning bearings are provided for journaling the ends of a rotatable shaft.

In general, the unit of the present invention comprises an inner bearing member of elastic material, such as sintered powdered metal, having a spherical outer diameter and a cylindrical inner diameter or bore. The spherical outside diameter of the bearing is substantially enclosed by a rigid one-piece metal housing cast thereabout. The spherical outer diameter of the bearing permits it to pivot within the rigid housing to allow for alignment of a shaft journaled in the bearing.

Large scale commercial production of a unit of the foregoing type has been restricted at the present time, the basic problem therein being casting of a movable spherical insert into a rigid housing and to compensate for the contraction of the housing on cooling. Without some means of compensating for this contraction, the insert is locked in place and as a result cannot be pivoted. One method for compensating for this contraction is to coat the insert with some material, such as a lubricant, which will be dissipated either in the casting process or afterward. The prime reason for making the latter impractical for consistent large scale commercial production is that of maintaining a uniform coating on the insert and controlling the dissipation of the coating. Another disadvantage of the aforesaid method is that when suflicient coating is obtained for subsequent pivoting of the insert, some means must be introduced to keep the insert from spinning on its axis.

The difliculties of the prior practices are overcome by the present invention which employs a pre-formed bearing composed of elastic material such as the aforesaid porous sintered powdered metal composition. Such porous sintered powdered metal material is elastic within limits and has properties of expansion and contraction and a high degree of elasticity, which properties are taken advantage of in the present invention.

Other objects and advantages of the present invention together with its details of construction, arrangement of parts and economies thereof will be apparent from a consideration of the following specification and accompanying drawings, wherein:

FIG. 1 is a perspective view of a unitary pillow block formed in accordance with the present invention, and

wherein a bearing of the character aforesaid is pivotally disposed and retained within a one-piece metal housing cast thereabout, the housing being of the two-bolt flange mounting type.

FIG. 2 is an exploded view showing the means for casting the metal housing about a pre-formed sintered powdered metal bearing in accordance with the present inven tion with one die cavity and the bearing in section, and is thus to be considered a diagrammatic view of a die casting component. 1

FIG. 3 is a section of the bearing component disposed on a core of one of the die components shown in FIG. 2.

3,254,926 Patented June 7, 1966 FIG. 4 is a section through the closed die components and the embraced bearing of FIG. 2.

FIG. 5 is a section on the line 55 of FIG. 3.

FIG. 6 is a section on the line 6-6 of FIG. 4.

FIG. 7 is a section similar to that which would be taken on the line 66 of FIG. 4 after the die components have been separated from the unitary pillow block.

FIG. 8 is a diagrammatic View showing a plurality of housings cast in one mold, for example in a metal casting die, before separation.

Referring to the drawings, the reference numeral 10 generally indicates a one-piece metal housing, for example, aluminum, cast about the bearing generally indicated as 11. The housing is formed with a pair of flanges 12, 12 each having a hole 13 for reception of a mounting bolt. It will, of course, be understood that the illustrated pillow block unit is for the purpose of illustration and not limitation. Thus, for example, the housing may have a threebolt flange mounting and in lieu of the axis of the bearing 11 being parallel to the axes of the bolt holes 13, 13, it will be understood that the unit may be in the form of the standard mounting wherein the axes ofthe bolt holes 13, 13 are perpendicular to the axis of the bearing 11. Of course, the flanges 12, 12 will then be at an angle of 90 to that shown in the illustration of FIG. 1. Alternatively the housing may be formed without attachment flanges so that the outer surface of the portion which embraces bearing 11 is cylindrical and is later pressed into a cylindrical holder by the user.

The bearing 11, as employed in the present invention, is preformed of conventional powdered metals, typical compositions of which are 90% copper and 10% tin; 77.5% copper, 7.5% tin and 15% lead; 25% copper and iron; 20% copper, 79.5% iron, and 0.5% carbon, and the like. A further alternative can be straight iron. These compositions are given for the purpose of illustration and not limitation. The bearings are composed of compressed powders which are sintered in conventional manner to result in compositions having a resilient spongelike character. These are conventionally employed for selflubricating hearings in that they are porous and can contain approximately 25% of lubricating oil by volume stored in the tiny interconnected pores of the preformed bearing, this type being known as'an Oilite bearing.

As shown in FIG. 2, the bearing 11 is formed initially with a cylindrical bore 14 and a spherical outer surface 15. In casting the housing 10 about the bearing 11 in accordance with the present invention, the bearing 11 is first seated on the core pin 16 of the die component 17, the diameter and length of the core pin 16 being such as to snugly seat the bearing 11. Thereafter, the second die component 18, having a cavity 19 therein shaped to form the housing 10, is closed against the die component 17. It will be noted that the die component 18 includes the tapered mandrel 20 which is adapted to be received within the tapered hollow 21 of core pin 16. As appears from FIGS. 5 and 6, the core pin 16 is formed with one or more longitudinal slots 22. The tapered mandrel 20 is slightly larger than the normal dimension of the tapered slot 21 so that when the mandrel 20 is inserted within the aperture 21 and driven home and the two die components 17 and 18 brought together, the slotted core pin 16 is caused to expand and at the same time it expands the bearing 11 mounted thereon.

It will be understood that although the drawings illustrate the core pin'16 to be formed with two slots, one or more than two can be employed for the same purpose. The material of which the bearing 11 is composed being resilient and compressible, will become slight-1y compressed and expand as a whole when it is disposed bet-ween the two closed die halves as described, and before the housing is cast thereabout. This expansion, due to the means employed, is somewhat unequal. That is to say, when the mandrel 20 enters the slotted core pin :16 it forces the core pin to expand in one directional plane only, thereby forcing the bearing 11 to expand but not equally in all directions. This creates a slight out-of-round condition on the outside surface 15 of the bearing and a corresponding ou't-of-round condition in the pocket or bore 2 3 of the housing 10 when cast there-about.

The amount of expansion of the core pin 16 and its embracing bearing 11 can be controlled by the relative tapers of the mandrel 2t) and tapered slot 21 and consequently the amount of expansion transferred to the bearing 11 can be similarly controlled in a calculated manner.

Thus, after the die halves are closed as shown in FIG. 4, and the molten metal poured into the die cavity through suitable gate and sprue means, not shown, but as is apparent to those skilled in the casting art and is apparent from FIG. 8 of the drawings, and about the expanded bearing 11, the housing 10 is formed with a mating surfaced bore 23 which, although substantially spherical, is slightly outof-round for the reasons previously described. Desirably, also and for facility in subsequent pivoting as will be explained, the rear of the substantially spherical seat of the housing is less than that of the substantially spherical segment surface .15 of the bearing '11.

The housing mate-rial metal as it cools shrinks tightly around the bearing Ill. It will be'understood that no coating has been employed between the outer surface of the bearing 11 and the cast face of the housing 23 and the bearing 11 as employed in the practice of the present invention is dry during casting and subsequently impregmated with oil.

When the die sections 17 and 18 areseparated the rnandrel 20 is withdrawn from the core pin 16 allowing the core pin to return to its original size, whereupon the bearing 11 due to its resilient nature also return-s to approximately its original size. However, some set takes .place so that for example the bearing 11 will contact approximately 80% of the amount of initial expansion thereof. This, of course, relieves the strain of the shrink- :age of the housing 10 and results in separation of the bearing 11 from the bore 2?) of the housing 10, providing a slight separation sufiicient to permit pivoting but not axial spinning of the bearing 11 within the housing 10.

Thus a self-aligning pillow block is formed but at the same time the bearing 11 is positively retained within the housing 10. Furthermore, due to the induced slightly out-of-round condition of the bearing 11 and the out-ofround internal diameter or substantially spherical bore 23 of the housing 10 there-about, undesirable spinning of the :bearing 11 within the housing 10 is prevented. In other 'words, while the contraction of the bearing 111 after removal from the die will permit ease of pivotal motion due to self-separation of the bearing 11 from the bore of the housing It the slight out-of-r-ound condition of each will prevent the hearing from spinning on its axis. However, due to the pivot-ability of the bearing 11 within the housing 10, the slight out-of-round condition of each will prevent the bearing from spinning on its axis. However, due to the pivotability of the bearing 11 within the housing 10, it is possible to compensate for initial or subsequent minor misalignment of a shaft journaled in the bearing 11 and to thereby relieve undue stress on either the bearing or the shaft or both.

The housing 10 needs only to be bolted in place by means of suitable bolts engaged through the holes 13 in the integral flanges 12 to provide a bearing surface for a rotatable shaft. Thus, the device of the present invention provides a self-aligning bearing surface with a simple means of fastening the bearing to a suitable support and eliminates the need for costly alignment since ithC unique construction and arrangement of the parts automatically provides for self-alignment and the assembly relieves undue stress of the engaged rotating shaft in the bearing through application of a ball-jointlike unit.

Although I have shown and described the preferred embodiment of my self-aligning pillow block and preferred method and means for forming the same, it will be understood by those skilled in the art that various changes may be made in the details thereof without departing from the spririt and scope of my invention as comprehended by the following claims.

I claim:

1. A pillow block comprising a one-piece rigid housing formed with a substantially spherical bore, and a bearing composed of elastic sintered powdered metal material and formed with a cylindrical axial bore and having a substantially spherical outer surface snugly and pivotally disposed in and embraced by the defines of said substantial'ly spherical bore, the outer surface of said bearing and the defines of said substantially spherical bore being each slightly ou=t-of-round thereby retaining said bearing against rotation about its axis.

2. A self-aligning pillow block comprising a one pie'ce rigid cast metal bearing block formed with a substantially spherical bore, and a bearing composed of porous sintered powdered metal formed with a cylindrical axial bore :and having a substantially spherical outer surface of greater segment than that of said substantially spherical bore snugly and pivotally disposed in and embraced by the deiines of said spherical bore, the outer surface of said bearing and the defines of said substantially spherical here being each slightly out-of-round and thereby retaining said bearing against spinning on its axis within said housing.

References Cited by the Examiner UNITED STATES PATENTS a DAVID J. WILLIAMOWSKY, Primary Examiner.

FRANK SUSKO, ROBERT C. RIORDON, DON A.

WAITE, Examiners.

H. S. IGESER, R. C. RIORDON, F. R. SUSKO,

Assistant Examiners. 

1. A PILLOW BLOCK COMPRISING A ONE-PIECE RIGID HOUSING FORMED WITH A SUBSTANTIALLY SPHERICAL BORE, AND A BEARING COMPOSED OF ELASTIC SINTERED POWDERED METAL MATERIAL AND FORMED WITH A CYLINDRICAL AXIAL BORE AND HAVING A SUBSTANTIALLY SPHERICAL OUTER SURFACE SNUGLY AND PIVOTALLY DISPOSED IN AND EMBRACED BY THE DEFINES OF SAID SUBSTANTIALLY SPHERICAL BORE, THE OUTER SURFACE OF SAID BEARING AND THE DEFINES OF SAID SUBSTANTIALLY SPHERICAL BORE BEING EACH SLIGHTLY OUT-OF-ROUND THEREBY RETAINING SAID BEARING AGAINST ROTATION ABOUT ITS AXIS. 